White LED lights

A couple of years ago I bought a Cateye HL/LD500 White LED Lamp and a
Knightlite Koncorde, a white LED version of their excellent BS approved
LED rear light. This article compares these two lights.

Recently I have also bought a Cateye HL-EL100, a three-LED light
that is shaped very much like Cateye's popular Micro Halogen front
light. The latter light is in an altogether different category than
the two smaller lights pictured above, as it it more of an alternative
to a proper front light. As such is reviewed in my Low-Power Lights Review article with other
proper front lights.

Indoor tests of the Cateye HL/LD500 and the Knightlite Koncorde showed:

the white LED lights were quite a bit dimmer than some benchmark
rear LED lights, like the VistaLite Super Nebula (5 LED light) and the
Knightlite/Halfords BS approved rear light.

they are much brighter than previous front LED lights made from
green, yellow, or orange LEDs

the Knightlite seemed brighter than the Cateye from some angles,
from the other angles the Cateye and Knightlite were the same
brightness

One night, I stuck them on bikes and had my boyfriend ride
around the block while I watched from our drive. Test results are as
follows:

the white LED lights seemed to be satisfactory as a "be seen" light

they not as effective (not as bright) as even relatively cheap
incandescent lights, like the Cat Eye HL500, which cost 15 quid or less,
on the other hand their bluish tinged light is unusual enough
that it may help attract attention

as in the indoor tests, the Cateye and Knightlite were about the
same brightness, except at a few angles where the Knightlite is
brighter

My conclusion regarding brightness is that they are superb as
backups to dynamo lights that don't have standlights, and can be
useful as a light to keep attached to your bike at all times, to be
turned on when you have an unplanned ride in the dark.

Since they aren't as bright as plain incandescent lights like the
Cat Eye HL500, they shouldn't be bought as your only front light to be
used at all times. However, if you do this, it's better than nothing,
as long as you keep fresh batteries in them to keep them as bright as
they can be.

Longer term use of both lights showed that the Cateye light lasted
much longer on a set of batteries than the Knightlite, despite the
fact that the Cateye has three LEDs while the Knightlite has only
one.

The Knightlite seems a better deal than the Cateye, since it's 13
quid (mail order from St John St Cycles) and includes batteries, while
the Cateye is 18 quid or more, and doesn't include batteries, and the
Knightlite is as bright or brighter from all angles. However the
Knightlite goes through batteries faster, so although it costs more,
the Cateye may prove less expensive to use in the long run. In
addition the longer run time means that you're less likely to be
caught without a light when you need it.

Durability. After discovering that the Cateye light has a
longer runtime than the Knightlite, I used that alone on my commuter
bike as a backup for my dynamo light. That is, until one time while
changing the batteries, it stopped working. I'm not sure what happened
to it: I didn't abuse it or (as far as I know) put the batteries in
the wrong way around, but for whatever reason it doesn't work any
more. Funny, the same thing happened with one of the Cateye red LED
rear lights. I'm not saying that these Cateye lights are bad, simply
that I've broken two of them simply in changing the batteries. I'm
sure others have gotten years & years of service out of them.

I also have some doubts about the durability of the Knightlites. I
have several of the red rear ones, and most of them have developed
cracks in the edges of the lenses. None has broken yet, so I don't
know if this is a serious problem... And after several years of use,
they still work, and the white front LED light still works as well,
although I hven't used it recently.